Opto-microfluidic system for the detection of PFAS with molecularly imprinted polymer particles
Source: BAM
Per- and polyfluoroalkyl substances (PFAS) are extremely persistent industrial chemicals whose detection usually requires complex laboratory methods due to their chemical stability, structural diversity, and often very low concentrations. Although these methods are indispensable for environmental monitoring and regulation, they are too slow and expensive for real-time industrial process control. Scientists at BAM have therefore developed a compact on-site system for rapid PFAS detection.
Instead of measuring all known PFAS – now numbering over 10,000 substances – the approach focuses on PFCAs, an important subclass with a carboxylic acid head group such as PFOA (perfluorooctanoic acid), which are commonly found in industrial wastewater. This enables measurements to be taken directly at the point of use, delivering results in about 15 minutes.
The technology is based on molecularly imprinted polymers (MIPs), synthetic materials with binding sites tailored to the shape and chemical properties of a target molecule. These polymers function like artificial receptors that selectively bind PFOA and other medium- to long-chain PFCAs. A fluorescent indicator is covalently integrated into the MIPs, which changes its signal when the target molecule binds. An optical readout device converts these signal changes into digital data.
The miniaturized platform combines liquid handling, chemical recognition, and optical detection in a compact format that is principally suitable for industrial applications. The prototype has already been successfully tested in the laboratory with real samples and is to be further developed into a robust, user-friendly instrument. Thanks to the modular design of the sensor particles, the detectable substance spectrum can also be extended to other PFAS subclasses.
The assay shows how molecular design, materials science, and device technology can be combined to create a practical analysis system. Such on-site methods facilitate quick decisions in industrial environments, improve process control, and thus contribute directly to environmental protection. They complement laboratory analysis and enable a multi-stage monitoring strategy. From a scientific perspective, the work shows how selective polymer-based recognition and miniaturized optical detection can be successfully integrated into a modular analysis platform.
Ratiometric detection of perfluoroalkyl carboxylic acids using dual fluorescent nanoparticles and a miniaturised microfluidic platform
Yijuan Sun, Víctor Pérez-Padilla, Virginia Valderrey, Jérémy Bell, Kornelia Gawlitza, Knut Rurack
Nature Communications, 2025